Folding apparatus

ABSTRACT

PCT No. PCT/DE91/00126 Sec. 371 Date Aug. 19, 1992 Sec. 102(e) Date Aug. 19, 1991 PCT Filed Feb. 19, 1991 PCT Pub. No. WO91/12195 PCT Pub. Date Aug. 22, 1991.In a folding apparatus with a collect cylinder (1) which can be switched from collect production to non-collect production, the holding elements and folding blades of which are connected with actuating elements, preferably embodied as scanner rollers (14, 15), which can be controlled by a respectively associated radial cam (12 or 13), the control area of which, preferably embodied as a control recess (16), can be selectively uncovered or covered by means of a cover device provided with cover cams (17) disposed on a drivable cam support (22) which is coaxial with the radial cam (12 or 13), a great variability in respect to feasible collect operations is attained in that the cover cams 17.1-17.8 of each cover device are received radially displaceable on the respectively associated cam support (22).

FIELD OF THE INVENTION

The invention relates to a control for folding blades and/or grippers ofa collector cylinder in a folding apparatus of a web-fed rotary printingpress.

DESCRIPTION OF THE PRIOR ART

The cover device contains a drivable cover disk with fixedly disposedcover cams. With an arrangement of this type it is necessary that thecover disk not only runs during collect production, but also duringnon-collect production, which often occurs in actual operation. With anarrangement of this type the number of successive collect operations isvery limited. Experience has shown that the limit is reached here withtwo successive collect operations. More than two collect operations areimpossible here.

On the other hand, the width of the printing press and with it that ofthe printing cylinder diameters is increased, so that the result is moreetchings (sides) at the circumference than previously for example eightetchings at the circumference.

SUMMARY OF THE INVENTION

It is the object of the invention to provide a control for foldingblades and/or grippers of a collector cylinder having seven grippersystems and seven folding blades, by means of which "partial collect" ispossible.

The advantages attainable by means of the invention consist particularlyin that the number of successive collect operations, and thus the numberof possible production types, can be increased with simple andcost-effective means. In an advantageous manner these are the followingproductions:

1. Non-collect, using 4U-, 6U- or 8U-printing cylinders,

2. Dual collect, using 4U- or 8U-printing cylinders,

3. Triple collect, using 6U-printing cylinders,

4. Quadruple collect, using 8U-printing cylinders,

5. Partial collect (non-collected signatures plus dual collectedsignatures), using 6U-printing cylinders,

6. Partial collect (non-collected signatures plus triple collectedsignatures), using 8U-printing cylinders.

"Partial collect" is understood to mean that not only non-collectedproducts, but also collected products are continuously generated in oneproduction position, for example C; A+B with 6U-printing cylinders, andA; B+C+D with 8U-printing cylinders.

It furthermore advantageous that practically a variable type of coverdisk is obtained and therefore more than two collect operations can beperformed.

The result is a more universal folding apparatus than before, by meansof which all products of a printing cylinder with up to eight etchingscan be easily collected on top of each other during one revolution,which allows the efficient production of even comparably thick products.Another advantage of the measures in accordance with the invention canbe seen in that the variable cover disk can simply stand still duringnon-collect production, in the course of which all or at least theinterfering cover cams are simply retracted, which is advantageous inthat unnecessary wear is prevented.

In an advantageous embodiment of the relevant measures, the cover camscan be adjustable by means of an adjusting disk which is coaxial to thecam support, can be driven together with the cam support and isadjustable in respect to the latter in the peripheral direction. Thismeasure permit a simple adjustment of the cover cam by turning theadjusting disk, which permits automatic adjustment. In a practical way,the cam support and the associated adjusting disk driven in the same waycould in this manner be drivably connected with each other by means of adifferential gear, which can be adjustable by means of an auxiliarydrive device which can be rendered passive during the production run.After having been set, the differential gear functions practically as aninherently rigid transfer organ.

A further advantageous step can consist in that the cam supports oradjusting disks associated with the folding blades and the retainingelements are each connected with each other fixed against relativerotation, and are preferably releasably clamped against each other.These measures permit a common drive of the two cam supports or the twoadjusting disks, which can make the structure very much simpler and atthe same time assures great accuracy. The radial cam associated with theretaining elements can preferably be adjustable in the peripheraldirection by means of an auxiliary drive device which can be renderedpassive during the production run. This makes possible an adaptation tothe respective production in the sense that shorter sizes are releasedsooner than longer ones.

A further advantageous measure for simplifying the pressure camarrangement and the adjusting disks can consist in that during collectproduction the cover device can be driven at different speeds, dependingon the number of the desired collect operations.

In a further advantageous embodiment of the relevant measures, the drivedevice associated with the cover devices can have an intermediate shaftwhich is parallel to the cylinder shaft, by means of which the camsupports can be can be directly driven and the adjusting disks can bedriven by interposition of the adjustable differential gear, and whichshaft can be coupled by means of a coupling element slidably disposed onit in exact register with each one of oppositely located drive wheels ofdifferent diameters disposed on it, so they are freely turning and andmeshing with different margins of a double wheel driven by a cylinderpart. In an advantageous manner this results in operational positionswith different drive speeds by means of the coupling element. By meansof this it is therefore possible in a simple manner to drive the coverdevices in the course of collect production as a function of the numberof the desired collect operations.

In the case of a double-width folding apparatus with folding blades andretaining devices distributed over the width of the folding apparatusand with control devices disposed in the area of both ends of thecylinder with associated cover devices, they can be simply drivable bymeans of a common intermediate shaft radially disposed outside of thecollect cylinder and extending over the length of the cylinder, so thata coupling device of the type sketched above is required in the area ofonly one cylinder end, which simplifies construction.

Further advantageous embodiments and useful further embodiments of therelevant measures ensue from the remaining dependent claims inconnection with the following description of a preferred exemplaryembodiment.

DESCRIPTION OF THE DRAWINGS

The exemplary embodiment illustrated in the drawings will be describedin detail below.

Shown in the drawings are in:

FIG. 1 a longitudinal section through the drive and control device of acollect cylinder of a folding apparatus in accordance with theinvention,

FIGS. 2 to 8 views of a variable cover disk in accordance with theinvention, provided with retractable and extendible cover cams, indifferent cam positions for different types of production.

DESCRIPTION OF THE PREFERRED EMBODIMENT

The collect cylinder 1 of a variable folding apparatus shown in FIG. 1,such as is, as a rule, placed downstream of a web-fed rotary gravureprinting press, consists of two evenly drivable fixture supports,star-shaped in cross section, in the form of a laterally seated foldingblade part 2 and of a gripper part 3 seated thereon. The folding bladepart 2 has been provided with folding blades 5, actuable by means of anactuation device. The gripper part 3 is provided with gripper bars 8,actuable by means of an actuation device 6, and equipped with grippers7. Drive wheels 11 of equal diameter are fastened side-by-side on thebearing journals 9 or 10 of the folding blade part 2 or the gripper part3 and are disposed coaxially in relation to each other, and can becoupled by means of a bridging drive, not shown in detail here, forachieving an even drive with a simultaneous adjustment possibility.

For performing a folding operation, the folding blades 5 are extendedand the grippers 7 opened. Radial cams 12 or 13, disposed coaxially withthe cylinder axis, are provided for this purpose in the area of thefront face of the cylinder and are scanned by the associated actuationdevices 4 or 6. For this purpose the actuation devices 4 or 6 are eachprovided with two scanning rollers 14, 15, disposed on a common shaftnext to each other, of which the one scanning roller 14 runs on therespective associated radial cam 12 or 13, and the other scanning roller15 runs on a cover device, adjoining each one of the radial cam 12 or13, for lateral covering of the cam recess 16 on the side of the radialcam, by means of which the actuation of the folding blades 5 or thegrippers 7 is performed. The radial cams 12 or 13 arecircular-arc-shaped outside the cam recess 16 on the radial cam side.Depending on the production operation, the cam recesses 16 are exposedduring every rotation of the collect cylinder 1 (non-collect) or duringeach nth rotation of the collect cylinder 1 (collect) and are otherwiselaterally covered. For this purpose the cover devices are provided withcover cams 17.1-17.8, disposed parallel to the respectively associatedradial cam 12 or 13. The width of the scanning rollers 14 or 15corresponds to the width of the radial cams 12, 13 or of the cover cams17.

The radial cams 12, 13 are at rest in relation to the driven collectcylinder 1. The radial cam 12 provided for controlling the foldingblades 5 is fixed on a bushing 18 which encloses the outer bearingjournal 19 and is fastened on the housing. The radial cam 13 associatedwith the grippers 7 is fixed in a radially outer bushing 19, rotatablyseated in the machine frame, on which an adjusting tongue 20 isfastened, by means of which the gripper 7 can be adjusted in theperipheral direction for setting the opening time of the grippers 7. Theadjusting tongue 20 can be drivable by means of an auxiliary drivedevice in the form of an auxiliary motor etc. provided for setting theformat, or simply manually actuable. During the production run theadjusting tongue 20 is secured against rotation. The cover devices withthe cover cams 17 and associated with the radial cams 12 or 13 aredriven in relation to the stationary radial cams 12, 13 during theproduction run. For this purpose a toothed drive ring 21 is flanged tothe outer drive wheel 11, from which the drive of the cover devicesassociated with each of the two radial cams 12 or 13 is derived.

As shown schematically in FIG. 2 in connection with the cover deviceassociated with the radial cam 12 assigned to the folding blades, thetwo cover devices each comprise a cam support 22, disposed coaxiallywith the respective radial cams 12, 13, on which the cover cams17.1-17.8 are received, adjustable in a radial direction. The peripheralshape 23 of the cover cams 17.1-17.8 corresponds to a section of acircle with a radius corresponding to the radius of the circular radialcam 12, 13 formed outside of the control recess 16 in the form of aperipheral cutout. The peripheral shape 23 of the cover cams 17.1-17.8can be moved adjustment of the cover cams 17.1-17.8 from a radiallyouter active position, which coincides with the circular-arc shape ofthe associated radial cam 12, 13, into a passive position locatedradially inside of the control recess. In the active position, the covercam 17.1-17.8 laterally cover the recess 16 when passing it, so that,when passing over the control recess 16, the scanning roller 14 runningon the respective radial cam 12 or 13 is prevented by the adjoiningscanning roller 15, running on a cover cam 17.1-17.8, from falling intothe control recess 16 and triggering a folding operation, as indicatedat 15a. The actuation device associated with the folding blade 5, whichin FIG. 2 is just passing through the folding gap, however, can fallinto the control recess 16 and perform a folding operation, as indicatedat 14a. An adjusting disk 24, disposed coaxially with the cam support 22and flush in the axial direction with the cover cams and provided withfixed control cams 25 and peripheral cutouts located between them, isprovided for adjusting the cover cams 17.1-17.8.

Each of the cover cams 17.1-17.8 is fastened on a pivot arm 27, which ispivotably seated on the cam support 22 by means of a paraxial pivotshaft and provided with a radially inwardly protruding scanner 28, whichis pressingly maintained against the peripheral shape of the associatedadjusting disk 24 by the force of a pressure spring 29. The pressurespring 29 is seated in a cutout 30 of the associated cover cam 17.1-17.8and is supported on the one end on the inner end of the recess 30 on thecam side and on the other end on a pin 31, which extends into the recess30 and is fastened on the cam support 22.

Following the adjustment of the adjusting disk 24, the adjusting disk 24and the cam support 22 supporting the cover cams 17.1-17.8 are evenlydriven during operation, so that during operation the cover cams17.1-17.8 retain their position set by the adjusting disk 24. The drivespeed of the entire cover arrangement constituted by the cam supports 22and the adjusting disk 24 then is selected as a function of therespective production mode in such a way, that the respectively extendedcover cams 17.1-17.8 pass the control recess 16 in such a way that onlythe desired number of folding operations are performed.

Because the folding blades 5 and the grippers 17.8-17.8 associated withthem operate synchronously, the two cam supports 22 and the twoadjusting disks 24 of the respectively associated cover device can befixedly connected with each other in order to simplify the drive devicerequired for their operation. As can be further seen in FIG. 1, the tworadial cams 12 or 13 are accordingly placed at such an axial distancefrom each other that both cover devices, which are provided with camsupports 22 touching each other, can be placed between them. Theback-to-back disposed cam supports 22 are firmly clamped to each otherby clamping devices. The adjusting disks 24, which extend below therespective associated radial cam 12 or 13 facing the cover cams17.1-17.8 are screwed together with a spacer element 32 interposed, thethickness of which corresponds to the total thickness of theclamped-together cam supports. Two bushes 33, 34, disposed so theyextend over each other, are provided for seating of the cam supports 22or cover disks 24 connected with each other in the area between thebushings 18, 19 supporting the radial cams 12, 13, where the radiallyinner bushing 33 supports the cam supports 22 directly adjoining eachother, and the radially outer bushing 34 supports the adjusting disks 24connected with each other with the spacer element 32 interposed. Theradially inner edge of one of each of the adjustment disk 24 and one ofthe cam supports 22 extends as far as the associated bushing 33 or 34and is bolted to it. The respectively other adjusting disk 24 and therespectively other cam support 22 can terminate farther out. The spacingelement 32 extends with its spacing cheeks through openings, associatedwith them, of the cam support 22 fastened on the bushing 34. The othercam support 22 envelops the spacing element 32.

The bushings 33, 34 supporting the adjusting disks 24 or the camsupports 22 are rotatably seated and provided on their ends remote fromthe cylinder with flanged toothed drive rings 35, 36 of equal diameter,which are received in a chamber 37 bounded by the housing partscontaining the bushings 18, 19 on the side of the radial cams and whichis accessible from the gear box 38. The toothed drive rings 35, 36 arein engagement with associated intermediate wheels 39, 40 of equaldiameter, which are seated on the side of the frame. In this case theintermediate wheel 40 seated in the drive train associated with the camsupport 22 is in engagement with a pinion 42 wedged on an intermediateshaft 41 disposed parallel with the cylinder axis outside of the collectcylinder diameter. The intermediate wheel 39 belonging to the drivetrain of the adjusting disks 24 is in engagement with a toothed ring 43of a double wheel seated on the intermediate shaft 41, the two toothedrings of the double wheel having the same diameter as the pinion 42. Thelatter is in engagement with the front wheel 45 of a differential gear46 disposed paraxially beside the intermediate wheel 41, the back wheel47 of which is in engagement with the second toothed ring 44 of thedouble wheel rotatably seated on the intermediate shaft 41. By means ofan auxiliary drive device 48, the differential gear 46 permits anadjustment of the back wheel 47 in respect to the first wheel 45 havingthe same diameter. The auxiliary drive device 48 is rendered passiveduring normal production, so that the differential gear 46 acts like aninherently rigid double wheel. The adjusting disks 24 can be broughtinto the desired rotational position by actuation of the auxiliary drivedevice 48.

For its part, the intermediate shaft 41 seated in the gear box 38 can bedriven at different speeds by means of the toothed drive ring 21 flangedto the outer drive wheel 11. A double wheel, seated on a journalfastened on the frame side and having two toothed rings 49, 50 ofdifferent diameter, is provided for this, which for their part are inengagement with drive wheels 51, 52 of different diameter, seated freelyrotatable on the intermediate shaft 41. The latter can be alternativelycoupled with the intermediate shaft 41 by means of a coupling part 53which is displaceably wedged between them. For this purpose, the drivewheels 51, 52 are provided in the area of their mutually facing frontends with two axially protruding coupling claws, so that the result isdefined coupling, in register. The coupling part 53 can be displaced bymeans of a gear lever 56 engaging a peripheral groove from a leftengagement position, shown in FIG. 1, into a right engagement position.Thus, two different speeds of the cover devices can be achieved by anappropriate movement of the gear lever 56.

As can be further seen from FIG. 2, in the exemplary embodiment shownhaving a seven-part collect cylinder 1, the cam support 22 is providedwith eight adjustable cover cams 17.1 to 17.8, the peripheral shape 23of which has an angular extent of approximately 10° to 20° each.

The eight cover cams 17 are distributed in two opposite groups, offsetfrom each other by 180°, of four cover cams 17.1, 17.2, 17.3, 17.4 inthe first group and 17.5, 17.6, 17.7, 17.8 in the second group, eachdistributed over an angular extent of 90°. Each of two cover cams17.1-17.5; 17.2-17.6; 17.3-17.7 and 17.4-17.8 are located diametricallyopposite each other.

In this case the adjusting disk 24 is provided with six fixed peripheralcams 25.1 to 25.6, which are distributed in two groups of threeperipheral cams 25.6, 25.1, 25.2; 25.3, 25.4, 25.5, offset by 180° fromeach other. The distances 1 to 6 (in angular measure) of the peripheralcams 25.1 to 25.6 are:

    ______________________________________                                        ≮ η 1 between peripheral cam 25.6 and 25.1                    = 56.25°;                                                              ≮ η 2 between peripheral cam 25.1 and 25.2                    = 48.00°;                                                              ≮ η 3 between peripheral cam 25.2 and 25.3                    = 75.75°;                                                              ≮ η 4 between peripheral cam 25.4 and 25.5                    = 56.25°;                                                              ≮ η 5 between peripheral cam 25.5 and 25.6                    = 48.00°;                                                              ≮ η 6 between peripheral cam 25.6 and 25.1                    = 75.75°;                                                              ______________________________________                                    

In contrast to the cover cams 17.1-17.8, the peripheral cams 25.1 to25.6 of the adjusting disk 24 have different peripheral lengths. Theperipheral cams 25.1 to 25.6 have the following peripheral length(=switch position length) in angular measure: Peripheral cam 25.1: 1° to2°; peripheral cam 25.2: 12° to 14°; peripheral cam 25.3: 22° to 24°;peripheral cam 25.4: 1° to 2°; peripheral cam 25.5: 12° to 14°;peripheral cam 25.6: 22° to 24°. The distance of the cover cams 17.1 to17.8, measured in angles of arc (angular measure), is:

    ______________________________________                                               ≮ α 1 between 17.1 and 17.2 = 45°                    ≮ α 2 between 17.2 and 17.3 = 15°                    ≮ α 3 between 17.3 and 17.4 = 30°                    ≮ α 4 between 17.4 and 17.5 = 90°                    ≮ α 5 between 17.5 and 17.6 = 45°                    ≮ α 6 between 17.6 and 17.7 = 15°                    ≮ α 7 between 17.7 and 17.8 = 30°                    ≮ α 8 between 17.8 and 17.1 = 90°             ______________________________________                                    

The distance between two cover cams is measured each time from half theperipheral shape length to half the peripheral shape length, the covercams 17.1 to 17.8 being in the extended position. This distribution ofthe cover cams 17.1 to 17.8 and of the peripheral cams 25.1 to 25.6 withthe peripheral recesses 26 of the adjusting disk 24 located between eachof the peripheral cams 25.1 to 25.6, together with the different drivespeeds of the present seven-part collect cylinder 1, make possible everydesired type of production from non-collect with the selectableemployment of 4U-, 6U- or 8U-printing cylinders (A+B; A+B+C; A+B+C+D);dual collect with 4U- or 8U-printing cylinders (AB; AB+CD); triplecollect, using 6U-printing cylinders (ABC); quadruple collect, using8U-printing cylinders (ABCD); partial collect, using 6U-printingcylinders (AB+C); partial collect, using 8U-printing cylinders (A+BCD).

The setting of the adjusting disk 24 in respect to the cam support 22and thus to the cover cams 17.1 to 17.8, which is the basis of FIG. 2,corresponds to the production mode non-collect with selectively 4U-, 6U-or 8U-printing cylinders, which results in a single-layer product. Theadjusting disk 24 is adjusted in such a way, that none of the cover cams17.1 to 17.8 are extended, i.e. each folding blade row 5 performs onefolding operation, each gripper row 7 opens during the foldingoperation, because each one of the seven folding blade rows 5 or gripperrows 7 finds an available control recess 16 during each rotation of thecollect cylinder and performs a folding operation. The same is true, ofcourse, for the gripper rows 7. None of the cover cams 17.1 to 17.8 isextended. The drive speed, i.e. the rpm, of the cam supports 22 and theadjusting disks 24 is 7/8 of the speed of the collect cylindersupporting seven folding blades and gripper rows each.

The setting of the adjusting disk 24 which is the basis of FIG. 3corresponds to the production mode dual collect with the employment of4U- and 6U-printing cylinders. A double-layer product is the result. Theswitch cams 17.1 and 17.4 or 17.5 and 17.8 are extended, the switch cams17.2 and 17.3 or 17.6 and 17.7 are retracted. The drive speed of the camsupport 22 and the adjusting disk 24 is 7/8 of the speed of the collectcylinder 1. The control roller of each folding blade row 5 or gripperrow 7 finds an uncovered control recess 16 during every second rotationof the collect cylinder and performs a folding operation, or the gripperrow 7 opens.

The setting of the adjusting disk 24 which is the basis of FIG. 4corresponds to the production mode triple collect with the employment of6U-printing cylinders. A triple-layer product is the result. The firstand third switch cams 17.1 and 17.3 or 17.5 and 17.7 are extended, theswitch cams 17.2 and 17.4 or 17.6 and 17.8 are retracted. The drivespeed of the cam support 22 and the adjusting disk 24 is 7/6 of thespeed of the collect cylinder 1. The control roller of each foldingblade row 5 or gripper row 7 finds an uncovered control recess 16 duringevery third rotation of the collect cylinder and performs a foldingoperation, or the gripper row 7 opens.

The setting of the adjusting disk 24 which is the basis of FIG. 5corresponds to the production mode quadruple collect with the employmentof 8U-printing cylinders. A quadruple-layer product is the result. Theswitch cams 17.1 and 17.4 or 17.5 and 17.8 are extended, the switch cams17.2 and 17.3 or 17.6 and 17.7 are retracted. The drive speed of the camsupport 22 and the adjusting disk 24 is 7/8 of the speed of the collectcylinder 1. The control roller of each folding blade row 5 or gripperrow 7 finds an uncovered control recess 16 during every fourth rotationof the collect cylinder and performs a folding operation, or the gripperrow 7 opens.

The setting of the adjusting disk 24 which is the basis of FIG. 6corresponds to the production mode partial collect with the employmentof 6U-printing cylinders, i.e. six copies (for example A, B, C, A, B, C)around the periphery. A single-layer plus a dual-layer product is theresult. The switch cams 17.2 and 17.6 are extended, the switch cams17.1, 17.3, 17.4, 17.5, 17.7 and 17.8 are retracted. The drive speed ofthe cam support 22 and the adjusting disk 24 is 7/6 of the speed of thecollect cylinder 1. Each field on the collect cylinder 1 is controlledin such a way, that the folding blade row 5 or the gripper row 7 findsthe control roller of a control recess 16 after one rotation and thenmust rotate twice until it again finds an uncovered control recess 16.

The setting of the adjusting disk 24 which is the basis of FIG. 7corresponds to the production mode partial collect with the employmentof 8U-printing cylinders, i.e. eight copies (for example A, B, C, D, A,B, C, D) around the periphery. A single-layer plus a triple-layerproduct is the result. The switch cams 17.2 and 17.4, 17.6 and 17.8 areextended, the switch cams 17.1, and 17.3 or 17.5 and 17.7 are retracted.The drive speed of the cam support 22 and the adjusting disk 24 is 7/8of the speed of the collect cylinder 1. Each field on the collectcylinder 1 is controlled in such a way, that the folding blade row 5 orthe gripper row 7 finds the control roller of a control recess 16 afterrotation and then must rotate three times until it again finds anuncovered control recess 16.

The structure and mode of operation of the cover device associated withthe gripper control corresponds to the cover device of the folding bladecontrol which is the basis of FIGS. 2 to 8 with only the difference,that the grippers 7 holding the start of the sheet have already passedthrough the folding gap when the folding operation is performed. Thus,activation of the folding blades 5 and opening of the grippers 7 takesplace essentially simultaneously. However, these operations extend overa definite period of time, so that the opening of the grippers 7 duringprocessing of short products should take place slightly sooner than inprocessing of longer products, which can be accomplished by means of theabove described pivotability of the radial cam 13 on the gripper sidebecause of the adjusting tongue 20.

In the case of a so-called double-wide folding apparatus, on which twoproducts lying side-by-side can be processed, the gripper bars 8 and thefolding blades 5 are distributed over the length of the cylinder and aseparate control device is associated with each cylinder side. Theconstruction of these two control devices can correspond to theconstruction of the control device for the right cylinder half shown inFIG. 1, only with the difference that the intermediate shaft 41 cannotbe coupled with the cylinder drive by means of an associated clawcoupling, but is connected with the opposite intermediate shaft 41 bymeans of a bridging shaft 57, as can also be seen in FIG. 1. Thisresults in a common drive shaft extending over the entire cylinderwidth.

In the above described exemplary embodiment the adjustment of the covercams takes place via associated adjusting disks 24, which makes possibleautomatic pre-setting by appropriate programming of the auxiliary drivedevice 48. However it would also be easily conceivable to adjust thecover cams 17.1-17.8 individually by hand in accordance with anappropriate guide. For this, the cam supports 22 would have to be simplysupplied with suitable clamping devices for fixing the cover cams17.1-17.8.

For setting the various production modes, the adjusting disk 24 with theperipheral cams 25.1 to 25.6 is set each time in such a way, that thecover cams 17.1 to 17.8 are brought into a position where the gripperrows and folding blade rows are activated at the correct moment. Toswitch the various production modes around, the adjusting disk 24 mustbe turned from the zero position ="production 4U-, 8U-non-collect" by anangle λ 1 to λ 5, so that the cover cams 17.1 to 17.8 are brought intothe desired position. Thus, the adjusting disk 24 must be turned fromthe zero position by λ 1=0.5° counterclockwise in order to bring thecover cams 17.1 to 17.8 into the production position "6U-non-collect".

The adjusting disk 24 must be turned by λ 2=24° in order to bring thecover cams 17.1 to 17.8 into the production position "4U- or8U-dual-collect".

The adjusting disk 24 must be turned by λ 3=12° in order to bring thecover cams 17.1 to 17.8 into the production position"6U-triple-collect".

The adjusting disk 24 must be turned by λ 4=34° in order to bring thecover cams 17.1 to 17.8 into the production position"8U-quadruple-collect".

The adjusting disk 24 must be turned counterclockwise by λ 5=12° inorder to bring the cover cams 17.1 to 17.8 into the production position"8U-partial-collect".

The adjusting disk 24 must be turned clockwise by λ 6=22° in order tobring the cover cams 17.1 to 17.8 into the production position"6U-dual-collect".

4U- 6U-, 8U-printing means that there are 4 (for example A, B, A, B) or6 (for example A, B, C, A, B, C) or 8 (for example A, B, C, D, A, B, C,D) copies (pages) of equal length disposed evenly spaced around theperiphery of the printing cylinder. The copies of 4U, 6U and 8U are ofequal length and can be variable within the permissible format size.

I claim:
 1. A folding apparatus, in particular a variable foldingapparatus for a web-fed rotary gravure printing press, with a collectcylinder which can be switched from collect production to non-collectproduction and is provided with seven holding elements embodied asgripper rows, and seven folding blade rows, the holding elements ofwhich are connected with actuating elements embodied as scanner rollers,which can be controlled by a respectively associated radial cam, thecontrol area of which, embodied as a control recess, can be selectivelyuncovered or covered by means of a cover device provided with eightcover cams disposed on a drivable cam support which is coaxial with theradial cam, the cover cams of each cover device are received radiallydisplaceable on the respectively associated cam support, the cover camsare adjustable by means of an adjusting disk, which is coaxial with thecam support, which can be driven together with the cam support and isadjustable in relation to the latter in the peripheral direction,characterized in that a 6U-printing cylinder with six copies around itsperiphery is provided, that the folding apparatus is switched into theproduction mode "partial collect", that the second and the sixth covercam are extended, and the first, the third, the fourth, the fifth, theseventh and the eighth cover cams are retracted, that the cover cams areextended for rendering the gripper rows and folding blade rows passive,and are retracted for the activation position.
 2. A folding apparatus inaccordance with claim 1, characterized in that the drive speed of thecam support and the adjustment disk is 7/6 of the speed of the collectcylinder.
 3. A folding apparatus, in particular a variable foldingapparatus for a web-fed rotary gravure printing press, with a collectcylinder which can be switched from collect production to non-collectproduction and is provided with seven holding elements embodied asgripper rows, and seven folding blade rows, the holding elements ofwhich are connected with actuating elements embodied as scanner rollers,which can be controlled by a respectively associated radial cam, thecontrol area of which, embodied as a control recess, can be selectivelyuncovered or covered by means of a cover device provided with eightcover cams disposed on a drivable cam support which is coaxial with theradial cam, the cover cams of each cover device are received radiallydisplaceable on the respectively associated cam support, the cover camsare adjustable by means of an adjusting disk, which is coaxial with thecam support, which can be driven together with the cam support and isadjustable in relation to the latter in the peripheral direction,characterized in that an 8U-printing cylinder with eight copies aroundits periphery is provided, that the folding apparatus is switched intothe production mode "partial collect", that the second, the fourth, thesixth, and the eighth cover cams are extended, and the first, the third,the fifth and the seventh cover cams are retracted, that the cover camsare extended for rendering the gripper rows and folding blade rowspassive, and are retracted for the activation position.
 4. A foldingapparatus in accordance with claim 3, characterized in that the drivespeed of the cam support and the adjustment disk is 7/8 of the speed ofthe collect cylinder.